CERN traps antimatter for long enough to do serious science on it

Researchers at CERN have boosted the efficiency of their method for trapping …

Earlier this year, a research collaboration at CERN announced that it had created a few dozen atoms of antihydrogen, the antimatter equivalent of the more familiar hydrogen atoms. These anti-atoms were kept in existence for just under 200 milliseconds before they annihilated in collisions with the container walls. Now, the same team is back with the announcement that it has created hundreds of atoms of antihydrogen, some of which were kept around for over 15 minutes—long enough to start contemplating doing some serious science with them.

The trap used to catch the antihydrogen is the same one used in the last experiment. It uses superconducting magnets to keep the antiatoms away from the container walls, taking advantage of the tiny magnetic moment created by the spatial distance between the antiproton nucleus and the positron (antielectron) orbiting it. The differences are so tiny that the trap will only work if the antihydrogen has an energy of 50μeV (micro electron Volt), which makes for quite a challenge, since the antiprotons start the process at 3keV. The big increase in the number of trapped atoms has largely come about through better ways of slowing down and cooling the starting materials.

The antiprotons are generated by bombarding a static target with a proton beam. The output is gathered and fed into a bit of hardware that is a bit unusual at CERN: a particle decelerator. These are slowed and cooled further by sending them through a cloud of cold electrons, after which some antiprotons are allowed to evaporate off, carrying even more energy with them; further evaporative cooling takes place after mixing with an excess of positrons. The team behind the work even figured out a way to push the positrons into a cooling chamber while imparting as little excess energy as possible.

Even so, most of the 6,000 antihydrogen atoms that are generated by a typical mixing are too energetic and bump into the trap's walls, ending their short lifetimes. Just a bit over half of the typical experiments result in an atom getting caught in the trap and being available for further studies.

It's not just the kinetic energy of the atoms that limits our ability to study them. The positrons are initially bound very weakly in the outer orbitals of the antiatom, and take a bit of time to reach the ground state by emitting photons. So keeping them around for longer is essential if we're going to study antihydrogen in its native state. Fortunately, the authors calculate that over 99 percent of the antiatoms will be in the ground state in a half a second, and there's so little gas contaminating the trap that the antiatoms should survive for hundreds of seconds on average.

In fact, they show that seven antiatoms survived all the way out to 1,000 seconds, or a bit over 15 minutes. In three tries, they also saw a single antihydrogen atom make it to 2,000 seconds, or over a half-hour. There's little doubt that these atoms spent most of their time in the ground state.

Most of the rest of the paper is spent comparing the predicted behavior of antihydrogen with where it eventually ran into the trap walls, creating a signal that the authors could locate. This data confirms that the antimatter is being created exactly as planned, and provides some information on how the trap is operating.

There's a lot of room to slow down the antiparticles a bit further before putting them into the trap, which would boost the efficiency considerably. Even so, efficiencies are already at the point where the authors suggest we can start doing detailed studies of antihydrogen, looking for ways in which it might differ from its regular matter counterpart. These include spectroscopic measurements to determine if the orbitals occupied by the positron are at identical energy levels to those in hydrogen.

The antihydrogen also survives long enough that we might start to consider performing some laser cooling to slow its kinetic energy down even further. This could slow the antiatoms enough that they'll become subject to measurable gravitational impact. In both these cases, theory predicts that antimatter atoms will behave precisely as regular matter does, with regularly spaced atomic orbitals and a weak, but measurable, pull from gravity. Any deviations from the expectations would have profound implications for physics, so you can bet that the team at CERN is eager to get started on this work.

Now, if they would just add dilithium to the periodic table, we are all set to build warp engines.

+1

Dang beat me too it. But I was going to say that we just need the dilithium matrix.

However...Dilithium does exist

Dilithium, Li2, is a diatomic molecule comprising two lithium atoms covalently bonded together. Li2 is known in the gas phase. It has a bond order of 1, an internuclear separation of 267.3 pm and a bond energy of 101 kJ mol−1.[1

Fascinating. Granted, this is nowhere near having matter/antimatter annihilation as a viable power source. But still, baby steps.

It would be weaponized before that. And then we won't need fancy power sources as the remaining humanity will go back to sticks and stones and, maybe, fire.

People also don't realize that m/am annihilation isn't nearly as spectacular as large particle fission. Fissile matter splits repeatedly down until it hits some level where there aren't enough neutrons to allow it to continue any further. It's not one reaction but several, in phases.

Fascinating. Granted, this is nowhere near having matter/antimatter annihilation as a viable power source. But still, baby steps.

It would be weaponized before that. And then we won't need fancy power sources as the remaining humanity will go back to sticks and stones and, maybe, fire.

People also don't realize that m/am annihilation isn't nearly as spectacular as large particle fission. Fissile matter splits repeatedly down until it hits some level where there aren't enough neutrons to allow it to continue any further. It's not one reaction but several, in phases.

I certainly wouldn't advocate it as the only good option; fusion would also be wonderful if we could get it working. To refer back to another recent article, rather than focusing narrowly on ideas that are obviously good, we should foster circumstances where lots of non-terrible ideas are floating around.

That said, it wouldn't surprise me if the government had tried to weaponize flower power back in the '60s, so yeah, we really should try to put some limits on this very soon.

This is amazing research. Any news on how long the equipment lasts before the strains induced by the antimatter impacts destroy it? I'd imagine losing electrons and even transmuting the nuclei in the chamber has got to do something to it.

Fascinating. Granted, this is nowhere near having matter/antimatter annihilation as a viable power source. But still, baby steps.

Not sure if that will ever be the case, at least not as long as we need to make the antimatter ourselves. At best it may be a energy storage system.

Quite right. But then again, everything is an energy storage system from a certain point of view... Only difference is who put the energy in. A working practical antimatter energy storage system would do just fine, thank you. I mean, it would finally free us of the Earth's gravity well. I'm pretty sure that if we get that working we can start sticking solar panels and transport railguns in orbit near Mercury and be on our merry way to a Kardashev Type 2.

Fascinating. Granted, this is nowhere near having matter/antimatter annihilation as a viable power source. But still, baby steps.

Not sure if that will ever be the case, at least not as long as we need to make the antimatter ourselves. At best it may be a energy storage system.

Quite right. But then again, everything is an energy storage system from a certain point of view... Only difference is who put the energy in. A working practical antimatter energy storage system would do just fine, thank you. I mean, it would finally free us of the Earth's gravity well. I'm pretty sure that if we get that working we can start sticking solar panels and transport railguns in orbit near Mercury and be on our merry way to a Kardashev Type 2.

Until some terrorist hijacks the control system and aims it at some big city or other...

It is interesting in the fact that nobody can possibly predict what sort of technological marvels will pop up in result to this. Everybody says energy storage and weapons, when the final form will probably be something completely unrelated.

It is interesting in the fact that nobody can possibly predict what sort of technological marvels will pop up in result to this. Everybody says energy storage and weapons, when the final form will probably be something completely unrelated.

People also don't realize that m/am annihilation isn't nearly as spectacular as large particle fission. Fissile matter splits repeatedly down until it hits some level where there aren't enough neutrons to allow it to continue any further. It's not one reaction but several, in phases.

People also don't realize that m/am annihilation isn't nearly as spectacular as large particle fission. Fissile matter splits repeatedly down until it hits some level where there aren't enough neutrons to allow it to continue any further. It's not one reaction but several, in phases.

Yeah. M/AM annihilation is a complete mass to energy conversion isn't it? While fission is just the mass difference between the uranium starting atom and the resulting two atoms, which is a hell of a lot less energy (per reaction at least)

Yeah. M/AM annihilation is a complete mass to energy conversion isn't it? While fission is just the mass difference between the uranium starting atom and the resulting two atoms, which is a hell of a lot less energy (per reaction at least)

M/AM converts 50% of the energy into neutrinos. If you consider that in any way "useful energy," then I want to see your Nobel prize.

Fission and fusion are still far more useful to us because A) we can actually use the released energy and B) there are still particles left over that we can do other things with.